Where mask-wearing to protect against COVID-19 is mandated, a small proportion of visitors and staff in indoor public areas either do not wear them or wear them improperly. Research published in the open-access journal PLOS ONE found that in December 2020, 4 percent of visitors and 8 percent of staff in retail trade stores in Kentucky did not wear a mask, and 14 percent of visitors and 13 percent of staff wore them improperly.
Public health campaigns have emphasised the importance of mask-wearing during the COVID-19 pandemic; understanding real-world behaviour and practices can help with future policies and communications. Seyed M. Karimi and colleagues at the University of Louisville, Kentucky, USA, where a state-wide mandate was implemented in July 2020, logged observations of mask use behaviour in 382 randomly selected retail trade stores. Ten trained observers logged the prevalence of proper facial mask use as well as incorrect use, as effectiveness is limited if a mask is not used properly. 2,080 visitors and 1,510 staff were observed during one week in December 2020 at the peak of the pandemic in the United States.
There was variation in the proper use of masks depending on the size of the store, with visitors and staff in larger stores more likely to wear a mask, and to wear it correctly. Furniture, home improvement and equipment outlets had the highest compliance, and food and grocery stores saw more unmasked and incorrectly masked visitors and staff than other outlets. Districts with the highest prevalence of unmasked and improperly masked individuals were among the most economically disadvantaged districts of the city. Finally, of the observed visitors and staff, male middle-aged adults were the group most likely to be unmasked or improperly masked.
Karimi adds: "Mask use and proper mask use rates were lower in Louisville City districts with lower income, in smaller public areas, and in food and grocery stores. The majority of the observed unmasked persons were male and middle-aged."
